Start-stop repeater apparatus



June 15, 1943. 1.. M. POTTS START-STOP REPEATER APPARATUS Original Filed Nov. 30, 1934 INVENTOR. "LOUIS M. POTTS A TTO RNEY.

Patented .lune 15, 1943 START- STOP REPEATER. APPARATUS Louis M. Potts, Evanston, Ill., assignor to Teletype Corporation, Chicago, 111., a corporation of Delaware {)riginal application November 30, 1934, Serial No.

755,253, now Patent No. 2,262,356, dated Novcmber 13, 1841. Divided and this application March 3, 1941, Serial No. 381,461

Claims whereby the precise characteristics of each signal, impulses or impulse are reproduced under the control of the code combination signals re" ceived over the circuit. Where two remote stations are in communication each with the other, as through the medium of an interconnectingor central oflice station, there may be employed an intermediate repeating device capable of operating at high speeds for reproducing in original strength and wave shape each signal generated by either of said stations. Under such conditions of communication between two outlying stations, special apparatus has been provided to be used with a repeater unit associated with each station responsiveto the establishment of communication by the other of said stations whereby signalstransmitted to such station will not cause the repeating apparatus for the receiving station to be released for signal reproducing purposes. In this manner there is prevented the transmission back 'or reflection over the transmitting leg orthe circuit, signals directed to a receiving station. g Accordingly, the principal object of the prescut-invention is to provide repeat ng apparatus capable oi operating at high speeds to transmit signals over a communication line equivalent in strength and wave shape to the originally transmitted signals and. without effecting the trans mission back ofreflectedsignals to the transmitting station.

The foregoing and other objects of the present invention are attained by the provision of motor driven mechanically operated but signal con-- trolled repeating apparatus for reproducing all signalsincluding start and stop impulses from one communication lin section to another, with elements mechanically controlled for preventing the reflex transmissionof signals effective at the beginning of each code combination of impulses and continuing so until the 0nd of such code combination of impulses. 1

In its preferred embodiment, the present invention utilizes'two regenerative devices or units each of which includes a'cam operatedcontact set in which the contacts of the device are positioned in accordance with the character of incoming signal impulses and the setting timed by means of a motor driven series of cam projections. In addition, latching means are provided to prevent an inactive one of a pair of repeater devices from operating during the period of ransmission by the active one of said devices of a complete series of signals or signal impulses contituting a character of a start-stop permutation code. -By this arrangement there is prevented the release of inactive repeater unit as aresponse to the line signals generatedby an active oneoi a pair of units.

Fora more comprehensive understanding of the present invention, reference is had to the accompanying drawing and to the following detailed specification, wherein like reference char-. acters designate corresponding parts throughout and wherein I 1 h Fig. 1 is a diagrammatic circuit illustration of two line sections and a mechanical system of. interlocking members connecting together two regenerative repeater mechanisms in a single telegraph transmission line;'and

Fig. 2 shows a motor control system wherein either of two connected regenerative repeater devices may control a common motor which drives both of said devices.

Referring now more particularly to theillustration in Fig. l, the reference characters Nil and I68 illustrate two regenerative repeater units serving two sections of a single telegraph line and having a mechanical system of interlocking members which will. now be described. In this figure is illustrated only the repeating equip ment, but it is to be understood that the distant end of each line section 2 l 6 and 2 l3, respectively,

may be provided with the conventional print-- four cam or latching discs indicated I12, I13, I14, and I15.

The start disc designated I12 is held by a latch I8I, see also Fig. 2, which in turn is pivoted at I82 and which is provided with a holding tooth that restrains disc I12 by fitting into a notch or recess in the periphery thereof. A start latch I83 also pivoted at I82 is restrained by its engagement with armature I84 while the armature is in its attracted or marking position during the energization of magnet I85. Start latch I83 has a sidewardly extending projection I86 which may engage and correspondingly depress the stop latch I8I to cause the latter to become disengaged from and accordingly release disc I12. Start latch I83 also has a cam follower projection I81 which rides the periphery of restoring cam I13 which reconditions said latch I83 after each release by its armature I84.

Coincident with the start impulse intervals of each code combination signal, magnet I85 is deenergized, releasing its armature I84 to the influence of return spring I9I, whereupon said armature I84 is permitted to assume its so-called spacing position. At this particular instant in the cycle of rotation of cam sleeve IN the depression in the periphery of cam I13 is disposed opposite projection I81 of lever I83, thereby permitting said lever I83 to rotate counterclockwise under the influence of its spring I92 when, as just described, armature I84 is withdrawn from beneath its left extremity as may be seen in Fig. 1. Spring I92 being of superior force to spring I93 of latch lever I8I, the rotation in a counterclockwise direction on the part of lever I83 about its pivot I82 acts through sidewardly extending projection I86 to carry with it latch I8I, thereby lifting the latters holding tooth out of engagement with the shoulder on the periphery of disc I12.

As a consequence of the withdrawal of latch I8I from disc I12, cam sleeve I1I is permitted to enter upon one cycle of rotation, carrying with it carn disc I12 and cams I13, I14, and 15. Immediately that the depression in cam I19 passes over the location of projection I81, its continuous apex surface causes lever I33 to be cammed in a clockwise direction to resume its original position, as indicated in Fig. 1. consequence of the rotation of cam I15, its several apices I11 successively engage the follower projection 2I3 of a floating contact controlling member 28L Of principal importance in connection with the present invention, however, is theeflect of cam disc I14 during the aforedescribed cycle of rotation, in which the sole depression in its periphery is moved past the location of the follower projection I95 of a lever I96 pivoted at I91 presenting during the remaining portion of the rotary cycle to said projection I95 the continuous peripheral apex of said cam disc I14 and holding said lever I96 in an extreme clockwise position against the tendency of the mutual spring I99, which connects said lever I96 with a companion lever I95 relating to the auxiliary repeater apparatus I68 associated with the principal apparatus I61 now being described.

The opposite end of lever I96 terminates with a latching projection I98 which extends within a slot formed in an armature I84. When the follower projection I95 of lever I96 is aligned with the recess in cam I 14, lever I96 is permitted to rotate counterclockwise about its pivot I91,

Asa-

withdrawing the latching projection I98 from engagement with a cooperating shoulder in the slot or notch of armature I84, but when said follower projection I95 is cammed outwardly as by the continuous apex of cam I14, then lever I96 is rocked clockwise about pivot I91, causing the latching projection I98 to engage firmly against the inside slot surface of said armature I84, holding said armature in its marking position notwithstanding the fact that its controlling magnet I may subsequently become deenergized.

As a result of the rotation of cam disc I15 having the plurality of cam projections I11 which engage the follower projection 283 of floating member 2Ill, there will be communicated to said member 29I a number of movement impulses corresponding to the number of cam projections I11. Member 211i is principally supported upon a shaft 282 which fits into an open slot at one end thereof and within which it is mildly urged by a seating spring 203. At its opposite end member 28I is formed with an armature engaging fulcrum projection 2I4. Accordingly, when armature I94 is energized by magnet I85 and held in the left position as viewed in Fig. 1, fulcrum 2I4 is clear of the armature extremity, so that when a cam projection I11 engages follower projection 2I3. member 2! will be permitted to pivot about shaft 282, fulcrum 2I4 rising upwardly together with contact lever operating projection 2I2. However, when said armature I84 is released as by the deenergization of its magnet I95, then an innermost surface thereof is placed over said fulcrum projection 2l4 so that thereafter when one of the cam projections I11 engages follower projection 2I3, the movement upward on the part of member 28I is resisted because of the abutment between fulcrum projection 2M and the inner surface of said armature lever I84, causing instead the right extremity of said member 20I to become unseated from shaft 202 against the influence of spring 283, whereupon the contact lever operating projection 2II will rise to engage the mutual operating lever 284.

Depending upon whether projection 2| I or projection 2I2 engages said lever 204, the latter will accordingly be disposed about its pivot screw 2115 crank. Since armature I84 will be positioned to the left or to the right, depending upon whether a code combination signal is comprised accordingly of marking or spacing impulses, the effect of each cam lobe or apex I 11 upon the contact operating member 28I will accordingly be to close or open the contact pair 206 and to correspondingly reproduce a signal upon line 2I8, the permutational character of which will be controlled by the line impulses impressed upon magnet I85, but the precise wave shape of which will be con-' trolled invariably by the disposition of the cam apexes I11.

As a result, the reproduced signals on line 2I8 will partake of a wave shape corresponding to the original signals or, more accurately, to the shape of theoretically perfect signals, cam I15 being especially designed to obtain this result, though said signals impressed upon line 2 I82I9 will have no eifect upon the auxiliary repeating device since its armature I84 will be held stationary during the entire cycle of each signal on account of the shape of cam disc I14 acting upon I68 having the prime reference markings as the principal or effective machine, the result will be just reversed'to the aforedescribed manner of operation, with shaft 234 and its repeating unit including sleeve I'll rotating cyclically under the control of signals impressed upon lines 2IB2!9 and effective to accordingly energize and deenergize the winding of magnet I85. Some difference may be noted in the shape of lever M56 as compared with that of the first de- L scribed intercontrol lever 596. This difference is of a casual significance, however, since as may be noted the effective intercontrol between the two repeating units is identical. When cam disc I14 rocks lever I95 in a counterclockwise direc- 5 tion through engagement with its follower projection I95, the remotely situated armature blocking projection i555 acting upon armature I84 will effectively hold in abeyance the unit lfil,

just as in the aforedescribed manner of opera- 3 tion unit I58 was held in abeyance by the effective operation of unit lfi'i.

' It is to be noted that contact controlling lever 294 whose extremity forces into engagement with each other the contact points 2% when said lever 264 is in clockwise position or permits the latter members to come ajar when said contact lever 264 is in counterclockwise position, partakes of the nature of a controlling element which is effectively moved from marking to spacing and vice versa only where a succeeding line impulse differs from a preceding one in essential signal ling characteristics. That is,. where consecutive impulses are of the same essential signalling characteristic, member 2i under such conditions operating in a similar manner finds said lever 29 i repeatedly in the same position held by detent jockey 2i and since no change is produced upon said lever 29%, none will be had upon the contact pair 2%.

Interruption in the transmission. is eifected by opening the receiving line section for a suliicient period or interval whereupon during the stop signal condition of the transmitting line section the open circuit condition of the receiving line section will operate to seize the alternative repeating mechanism and to render the home re-- corder of the particular transmitting station unresponsive to the operating transmitter. In this way the transmitting operator is notified at his station that the receiving station. is desirous of transmitting a message.

In Fig. 2 there is shown additionally to the disclosure of i a motor control mechanism for the apparatus wherein a single motor drive system imparting rotation to both repeater units l6! and N38 is controlledto start by a signal in either of the two associated line sections.

Upon-a supporting panel 235 there are mounted two fixed supporting brackets indicated 2-32 and 232', each of which affords journal bearings, re spectively, for its associated one of the two shafts 23d and 23%. As has been said, a cam sleeve lll is carried upon each one of said shafts and each is driven through a friction clutch 236.

Also fixed upon the pivot rods I82, described above, are cam followers 238 and 238', the extremities of which follow in the thread of cam screws 24!] and 240. The cam screws are slidable upon their respective shafts 234 and 234' and are at all times under the tension of associated springs 242 and 242' being rotatable with their respective shafts through a longitudinally shiftable spline connection 24!. In close proximity to the screw cams 240 and 24B are an associated pair of snap switches generally indicated 2M and 2 3 5 each with an operating arm 246 engageable by the extremity flanges of its associated screw cams designated 248 and 250. In operation, cam follower 238 of each unit is stationary, longitudinally, but through its engagement with the threads of its associated worm the latter member including its extremity flanges 248 and 259 is moved as a unit by reason of rotation of the shaft 234 when the follower 238 engages the threads of its screw. When the assembly 2-t325ll moves toward the mounting panel 23!, flange 248 will engage switch arm 246 and move the latter so as to permit the opening of its as--' sociated contact pair 252. p

The rotary driving motor 255 driven from a source of power 255 when either of the contact pairs 252 or 252' is closed, operates through gear train 256 to drive a distributor shaft 25'! which carries a tributary driving worm for driving each one of the repeater drive wheels 258 and 258. The effect of control switches 2M and 244 upon the motor operating circuit is as follows: Receipt of a starting signal of spacing characteristic by line magnet 585, for example, deenergizes the latter element and. releases its armature lat, which by spring i9! is drawn from beneath its associatesL latch H33 permitting the latter to rotate freely upon its supporting shaft I82. Inso doing, projection 1860f lever Hi3 causes to be similarly rotated the latch lever i8l which normally holds against rotation the cam assembly ll'i, releasing the latter to clockwise rotation as viewed in Fig. 1. Since each of the latch levers Mil is keyed to its associated shaft 582, the counterclockwise rotation of said latch lever ill! will accordingly withdraw the cam follower 238 from the thread of its associated worm 2&0. As a result, worm 24'. will thereby be free to respond to the urge of its spring 2 52 and be thrust upwardly, as viewed in Fig. 2, until its flange 250 engages the extremity of switch arm 246, causing th latter to be snapped to its contact closing position In consequence, contact pair 252 will become closed completing the'circuit to motor 254 which will begin rotation and accordingly will impart rotationto shafts and 23 5. Thereafter, during the conclusion of each cycle of rotation when latch lever it! is permitted to resume its latched position as indicated in Fig. 1, cam follower 238 will be permitted to reingage the threads ofits associated worm M9 and cam assembly including the worm 241! and the discs 243 and 25! will again approach the panel 23! until a subsequent start signal repeating the aforedescribed release operation to armatur EM, lever I83, and latch 48!, again with-draws cam follower 238,111 con equence of which cam assembly M l and discs 2% and 250 will again be restored to the position for effecting contact closure.

However, since contact armfitt remains in contact closing position until such a time that worm follower 238 has remained within the threads of its worm 240 long enough to feed disc 248 downwardly to engage switch arm 246, the repeated release operations of worm 240 will be of such short duration as to have no effect upon the associated switch mechanism 244.

After the cessation of signalling, the absence of start signals will permit cam follower 238 to remain continuously in engagement with its as sociated cam worm 249 for an interval of time suflicient for cam 240 to move toward panel 231 until its flange 248 engages arm 245 to reverse the mechanical condition of snap switch 244, thereby opening its associated contact 252 to interrupt the circuit and accordingly to arrest the further rotation of motor 254.

When breaking the transmission line, as described in connection with Fig. 1 above, the original transmission over controlling line section 2l6 will operate motor 254 by control of the contacts 252 and the line break under the control of line section 2| 8 will operate latch l8! and cam follower 238' to reverse the mechanical condition of snap switch 244' to close its contact points 252' so that for a brief interval motor 254 will have its power circuit closed by contacts 252 and 252' in parallel. Accordingly, each of the snap switches 244 and. 244' will be reversed to open its contacts under the control of its associated cam 24!] or 24!! by control of its own line section 2 IE or 2| 8, and independently of the continuation or cessation of transmission under the control of the associated one of said pair of line sections. For this reason motor 254 may stop only when transmission has ceased upon both line sections for the duration of a suitable period of time.

While the present invention has been explained and described with reference to a particular embodiment thereof, it will be understood that certain changes and modifications may be adapted without departing from the spirit or scope thereof. Accordingly, it is not intended to be limited by the details of the accompanying drawing nor by the specific language in the foregoing description except as indicated in the hereunto appended claim.

What is claimed is:

1. In a telegraph repeating system, two line sections, two regenerative repeaters each comprising a cyclically rotatable signal pattern outlining member, one of said repeaters associated with each of said line sections to repeat impulses into the other of said line sections, and mechanical interlocking means interengaging said two members to prevent concurrent operation of said two members.

2. In a telegraph repeating system, two line sections, two regenerative repeater mechanisms each for repeating impulses from one of said line sections into the other of said line sections, a motor to drive said repeating mechanisms, a power supply circuit for said motor, a first contact pair operable in response to an initial signal in one of said two line sections, and a second con tact pair operable in response to an initial signal in the other of said two line sections, said first and second contact pairs connected in parallel in said power supply circuit to control said circuit alternatively and jointly.

3. In a telegraph repeating system, two line sections, two regenerative repeaters comprising cyclically rotatable members, one of said repeaters associated with each of said line sections and each having an armature responsive to signals in its line section to release for rotation its associated member to repeat impulses into the other line section, and means moved by one of said members into position to obstruct the armature of the other of said members.

4. In a telegraph repeating system, two line sections, two regenerative repeaters one associated with each of said line sections, movable parts in each of said repeaters released for cyclic operation by signals in its line section to repeat impulses into the other of said line sections, and mechanical means extending between said two repeaters operable by a movable part of one of said repeaters and placeable into the path of the movable part of the other of said repeaters for obstructing said other of said two repeaters during the cyclic operation of said one of said movable parts.

5. In a telegraph repeating system, two line sections, two regenerative repeaters including cyclically operative mechanisms, one repeater associated with each of said line sections to repeat impulses in one direction only into the other of said line sections, and means movable by the mechanism of one of said repeaters and interposed to prevent concurrent operation of the other of said mechanisms.

6. In a telegraph communication line, two regenerative repeaters each associated invariably with signal communication signals in one direction over said line and each having an armature to repeat impulses over said line and a rotatable member for determining the impulse periods of each signal, and means mechanically operated by one of said repeaters to obstruct the operation of the other of said repeaters to prevent the movement of the rotatable member of the other repeater during the transmission of communication signals in the direction associated with said one of said repeaters.

'7. In a telegraph repeating system, a line of communication comprising a plurality of consecutive line sections, a regenerative repeater mechanism associated witheach of said line sections, a movable part associated with each of said repeater mechanisms for demarking duplicate signals corresponding to signals incoming upon its line section, electromagnetic means responsive to initial impulses of said incoming signals for re leasing to cyclic operation its associated one of said movable parts, and mechanical means extending between one of said regenerative repeaters to another operable by said movable part of one of said repeaters to obstruct the manner of action of said other of said repeaters.

8. In an intercommunication telegraph system, two line sections, regenerative repeater mechanisms to repeat impulses into either of said line sections, a normally nonoperating motor rotatable to drive said repeating mechanisms, a power supply circuit for said motor, a contact operable in response to an initial signal in one of said two line sections, and a further contact operable in response to an initial signal in the other of said two line sections, said contacts and said further contacts connected in parallel in said power supply circuit to control said circuit by either contact.

9. In a communication line for permutation code telegraph signals, a pair of line sections, a rotatable signal reshaping apparatus associated with each of said line sections, a common power source for said apparatuses, a magnet in each line section for controlling the application of power from said source to the apparatus for reshaping of signals for the other of said pair of line sections, and a control circuit including parallel control switches associated with each of said apparatuses for supplying current to said source during the continued operation of either of said apparatuses.

10. In a repeating system, two line sections, a start-stop regenerative repeater associated with each of said sections for reproducing multiple-impulse signals, a cyclic motion element associated with each one of said repeaters, a control member with each of said repeaters responsive to the initial impulse of said multiple impulse signals to release its repeater for rotation, a member extending from each one of said elements to the other one of said elements so as to prevent the release of said other of said repeater elements during the cyclic motion of its said element.

LOUIS M. POTTS. 

